Time
10 hours 41 minutes
Difficulty
Beginner
CEU/CPE
12

Video Transcription

00:05
and this module. We're gonna cover PC monitors and the various types. First, we'll start with the traditional C R T monitor.
00:12
This has been around for quite a few years.
00:16
Usually tip lucky. It's a lot heavier big back end, not like the LCDs and flat screens we have today. Graphical representation of the back.
00:26
You could definitely tell us you're a tea by the size.
00:29
The size is due to the fact that it's the way the images projected on the screen. There's three electron guns
00:35
that shoot from the back
00:38
and shoot with very intensity so they don't actually shoot red, green and blue. What they do is shoot various intensities to the screen, which is coated in phosphor.
00:48
And so the Fosse for has red, green and blue elements in and depending on the intensity fired at that, Foss for will cause
00:56
a red or blue or green image, too
00:59
appear on the screen. And then you put that together. I mean, we're talking small but part of drawing an entire picture. But that electron gun is what makes the size of the C R T so much larger.
01:12
There's a ring of electromagnets that keeps that
01:17
electron gun focused and firing at the screen to prevent blurry.
01:23
Now the foster cardi releases visible light when struck by the electron gun like I just mentioned
01:26
distributes electrons at different tense see to make the phosphorus coating glow it certain colors red, green or blue. So each gun is designed fire a different intensity to activate
01:37
the proper Foss. For
01:41
there's also a shouting shadow mask, um, on the foster
01:46
behind the foster coating that filtered out incorrect electron beans that color to prevent discoloration.
01:53
So some of the important features when dealing with C. R. T is the horizontal vertical refresh rate. First will cover the refresh rate.
02:04
So when it's building the image the electron gun, he's gonna shoot horizontally across and build each dot of the pixel. Each dog of the image, much like a dot matrix printer would we're gonna go across and build that image. So they're also called raster lines when it goes and creates that line, and so is gonna start from the upper left
02:24
corner, go across and down and keep going back and forth, and the rate that does this
02:30
is called the horizontal refresh rate.
02:31
So the horizontal. How long it takes to build one line. I should rephrase that one line vertical refresh rate, the rate it takes to draw the entire screen and then go back and start over again at the top left corner
02:45
with C Artie's. Um, if you ever had the pleasure to work with them if he had a very low vertical refresh rate like you said in the software you were noticing, it give you a flicker. You said we're not right.
03:01
If it was too high, not only could damage the moderate,
03:06
it's give you a headache.
03:08
You would tell something's just not right to give your head a bit too high, but too high. It could definitely damage the monitor. Um,
03:16
so you want to make sure you consulted your manual? What the proper vertical refresh rate waas
03:23
for it. Sometimes it was guessing game where you would go through and said different Record fresh rates to determine which one
03:30
didn't give you a headache
03:35
s a resolution. So I mentioned pixels a little bit earlier, just few slides ago. It's one area the foster. It's that that's let that instance to help build the bigger picture. So the number of lines drawn on the number of times the gun turns on off the gun that's lighting the pixels with individually colored phosphorus. Determine the number of
03:54
pixels
03:55
used to create the image. So we're talking resolution. The number of horizontal pictures, pixels, times, number of vertical pixels
04:03
gives you your resolution. So most you've seen these terms quite often. You, so 800 by 600 is a common resolution. Size 10 24 by 7 68 And so we're going horizontal times vertical when we're talking about those
04:19
resolutions,
04:23
NATO often heard about you here actually referred to as the math and not the actual pixel count
04:29
that it was used to derive. We're talking about resolution, especially now in LCDs, so high resolution means more pixels,
04:38
so more pixels means a better quality image,
04:42
and Morgan fell the screen. So if it's a high resolution, you be ableto
04:46
fit more on the screen and it wouldn't get blurry. It would still be
04:49
very crisp, especially with pictures.
04:56
Every modern had maximum resolution due to physical limitations on how small it can make a pixel.
05:03
So now we don't see Sieroty that much at all. even in our regular TV's honor in our homes, they've almost been completely replaced by L. C. D s.
05:14
A lot thinner, a lot lighter. Also use a lot less power. So instead of a gun,
05:18
uh,
05:19
toe light the phosphor on the screen,
05:23
we're using liquid crystals that get electric charge. An electric charge determined the color that crystal is gonna turn inside the LCD. So it's a lot less power
05:32
and a lot less infrastructure than we had with the c r a T. And that's why they are a lot lighter
05:41
when talking about all seedy types. We have passive matrix, which was the first kind of LCD out. Ah, a lot slower and we mean slower. A lot slower refresh rate knots. Crispin Image
05:54
dual scan passive matrix refreshed two lines at a time to kind of overcome that slow blurriness that was in the original
06:00
most common. Nowadays we use TFT thin film transistor active matrix,
06:06
where one of more transistors control each color dot and that provides a faster picture display and a lot clearer picture, which were the problems with
06:15
passive matrix. This also applies with TV's. Also, it's almost the same technology
06:21
now the components of a LCD.
06:25
So we have the actual panel, which creates the image and that required a D C power. Just like a computer. The computer power supply takes a sea turns into D. C. To use inside the system. Same thing for LCD.
06:39
Ah, there's a backlight which actually lights up the image after the crystal's been decide what color it's gonna turn and ironically enough, and that actually requires a sea power,
06:48
Um, and use a cold cathode fluorescent lamp like you have
06:54
in the ceiling
06:56
s. So then there's also an inverter that converts to D. C back to a C
07:00
for the back lights and feeds power.
07:04
LCDs have what's called a native resolution,
07:08
Um, and that's where they're gonna operate their their best, so sometimes they won't operate above. That's a lot of times operate below, but when you're operating anything but the native resolution that the monitors designed to operate at, you're going to get a sub quality picture. It might look like kind of like the same kind of effect that we talked about with, uh,
07:27
the vertical resolution of the vertical refresh rate, where if you do it, if It's not native, it's gonna be kind of blurry or the image might shake on the screen. But the native native resolution would be West is designed to support. So you get the Christmas Christmas
07:44
that'll work.
07:45
Get the best looking image
07:46
without any blurring on the edges and best colors.
07:50
Most modern LCDs
07:55
will be able to talk over the cable to a computer to figure out what it's native resolution is in. The graphic card
08:01
will automatically set it to its name of resolution.
08:05
They're like they've got a lot sore
08:11
nits or the measurement of brightness produced by the back lights in an LCD
08:16
average LCD produces 300 minutes. 100 would be low brightness. A really high brightness would be something around 1000.
08:24
Just some numbers to be aware of when comparing the brightness levels of the brightness of a LCD. If you want one that has a good bright image, look at the number of minutes
08:37
we have LCD response rate, which the time it takes for the sub pixels convert from pure black to white and black again.
08:45
Excuse me.
08:48
This is measured by milliseconds lower the better. So one of the biggest complaints about all CDs in common is they can't reproduce black as well as a,
08:58
uh,
08:58
C R T could cause a C A. T was doing black by absence of light. Well,
09:05
you have You still have a backlight, so you're creating black
09:09
with an LCD. So one of the thing, especially when you're looking at home theater, is
09:13
creating the best black
09:16
because you're making black instead of just having natural black. Um, that's what we're talking about with the response rate
09:22
and then the refresh rate say was in Sierra T for the amount of time taken for the screen, you're completely update,
09:26
uh,
09:28
is measured in Hertz.
09:33
There's also some LCDs use l ladies
09:37
light emitting diode to directly illuminate the pixels. Instead of using that backlight technology like we talked about with the catheter tube,
09:45
you see ladies and more commonly in mobile devices like phones. But
09:50
we're see the technology now in some LCDs Opera visor. Greater contrast. Ah, skinnier also requires less power. Everything's about energy. Conservation
10:01
doesn't require the a sea power, so there's no inverter. Another is, so it makes it lighter, too. That's no power inverter, Um,
10:07
and because of all these reasons. That's why you see in alive your phones and mobile devices is using eh ladies instead. But they usually cost more.
10:16
It's a more expensive technology.
10:20
Elsie finish. We're talking about the quality of the screen, so we have Matt, which is the industry standard that come from rise between the quality of color and glare reduction.
10:30
Uh,
10:31
it's washed out in areas of bright light, so
10:35
that's what you see on most of your average. But when we're talking home theater a lot times, you'll see Ah, high gloss, which is a shiny er screen
10:43
with Richard color and wider viewing angles, and by wider, wider viewing angles. We mean,
10:48
Okay, I'm standing straight on. You shall be able to see it, but some LCDs, depending on their finish as you come to the left of the screen, stays the same and you overto left. It's not gonna look quite right.
11:00
And so, with the high gloss you, it still looks good from an angle, which is something you want.
11:05
Ah, home theatre set up because you have multiple people watching it, sitting around a room as opposed to an industrial setting where you're sitting on a desk and you're just there. That's not usually need thio
11:16
see at an angle.
11:22
One last technology that falls under kind of the LCD category is called organic light emitting diodes or ol Ladies.
11:30
It's an organic film that lights and specific spots when charged by electric current. What's neat about this is because it's an organic technology. It could be used in like bendable displays. That's what started the experimental and like you can see here, the phone
11:45
being kind of a pliable,
11:50
doesn't use back lights but been mainly used on mobile devices
12:00
projectors. So projectors have come a long way to so we used to have the, uh,
12:05
the same with the guns. Now they're more like lamps.
12:09
There's two types projectors. We'll see. So we have a rear type projector where well, that's what this is. There's no we have a screen being displayed, but there's no image being projected in front of me. I can stand in front of here and there's no shadow. That's because
12:26
there's a rear projector. So what that means is they're projector behind the screen,
12:31
pointing at the back of this, and then we're seeing it from the front.
12:35
That's real projection. Front projection is if it was sitting
12:39
right here in shining Allinson TV like you'd see in a movie theater. You definitely know that because if I was standing here, then I would be blocking the image from the projector. Being in front of me, most projectors are capable of doing both. It really depends on the what kind of step you can support and
12:56
and where you're using the projector, because it does require an additional amount of space behind
13:01
where your screen is gonna be. But
13:03
to be out of support, a rear projection about the same time. It's nice because I can stand here and
13:09
we don't get a shadow, and you could still see everything. But for a quick set up, if you're traveling or you're just doing a quick presentation, most likely you would do a front projection setting because you just set it down and go the backs. The rear projection requires a little more work.
13:33
Some of the concepts in regards thio projectors. We have lumens, which is the amount of light given off by a light source in the projector. This determines the brightness
13:45
medium sized room requires 2000 lumens. Depending on the sides of room, the project is going to need brighter so that everyone can see it.
13:52
Uh, throw is Thea on screen image size from a distance. So how big it's, um, look. So the throw is How far do I have to get put the projector to make it fit into a
14:03
into my projected area?
14:05
No pun intended,
14:09
um,
14:09
on the lamps are actually generate the light used by the projector.
14:15
A quick no on lamps. They're usually like ink, an ink jet printer. The lamps are the most expensive part
14:22
of a projector, so help preserve your lamps and very common. One is turned off your projectors whenever you're not using them, because it's like it's like just wasted hours. They're usually good for so many hours of illumination, and that's a really good way to burn out. Is by
14:39
leaving a projector on unnecessarily. Like I said, they're almost as much as the projector of the cost of the lamp.
14:45
There are the bulbs,
14:46
um, and nothing to be aware of is they're very sensitive to Greece on by greasing like finger grease or oil is in your hands.
14:54
So when you go toe put in a new ball, be very cautious that you're using some kind of gloves or anything, because that can also shorten the life because that oil or grease will start burning out the bob.
15:07
They're very sensitive because it involves getting very hot in the grease with the oily fingers in the um
15:13
he can cause problems,
15:20
and you should always have a spare of lamp when you go somewhere with your projector
15:24
happened way too many times. That
15:28
that's that's when the lamp goes, is when you're not home.
15:33
It's like it's like the football for the new code. You have the lamp and bring that with you. Have someone else carry it,
15:43
um,
15:46
and last to talk about plasma display panels or P D piece. Another kind of flat screen display monitor. You had better picture quality and are less expensive than LCDs. Um,
15:56
they consume more power. Though heavier, they're more susceptible to burn in, which is you. Leave the same image
16:03
on the screen for so long for a shirt for for over an extended period of time, that image will start showing up. When the screens off, you'll start burning itself from the screen. LCD don't have that problem. Uh, plasmas do
16:18
on they have. They're susceptible to over scan, which means the image on the screen is blowing toward itself. You have, like, a wide screen movie, and it might show up beyond the borders of your
16:30
of your screen. So you're not.
16:30
That's called over scan. We're taking up more space than it's supposed to, but it's basically being cut off. You're not going to see that space because
16:37
screen can't fit it.
16:41
So we have modern versus viewable image size. Mater size is the Dyna length of the entire motor, including border. So you'll see this a lot. They'll be like you have a 32 inch monitor, while the 32 inch is the 32 inch
16:56
the viewable space, which is actually what you're gonna see for a screen
17:00
cause. Or is it the size of
17:03
the whole monitor itself sometimes will say, Okay, you have a 32 inch for that 32 inches, Matt measuring. So we'll pretend that this the TV
17:12
So are we measuring from this corner by the black
17:17
all the way to the other corner on the black as her size or remorse. Oring. Are we measuring from where the image starts in the corner,
17:25
toward the image stops in the corner on that side. So in this case, I mean, I guess would be off by like an inch. I mean, we'd be, too, in short on comparing our
17:34
sizes for our monitor size versus our viewing size.
17:38
So those were something to be aware of when shopping for minors is okay, Is it? 32 inch viewing size or 32 inch monitor size? Could theory two inch moderate size, and you're probably getting gypped because of the size of the
17:52
frame around it.

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